I sav it on otn before but it was machined on some how Posted by ash the machinist 1) they must accurately clock and center the rim per side - to ensure it comes out even, 2) they need a HSS (High Speed Steel) cutter ground to a point 25-40 degree included angle on fly or single-bar cutter. 3) for a dx32, they should aim for 0.35mm depth of cut, + or - 0.05mm, under no circumstances should they exceed 2/5 of the thinnest part of the wall thickness. 4) cutter dia = 350mm 5) cutter PCD = 420mm 6) cutter V = 50-60 m/min @ 70mm/min (70mm/min is the feed rate, using 70mm/min @ 54.9m/min, the speed, will give you thesame groove et/vb/showthread.php?t=12609